Non-aqueous electrolyte and lithium secondary battery including the same

Abstract

A non-aqueous electrolyte and a lithium secondary battery including the same are disclosed herein. In some embodiments, a non-aqueous electrolyte includes an organic solvent, a lithium salt, and an additive, wherein the additive includes a compound represented by Formula I and a compound represented by Formula II wherein, in Formula I, R 1 is an alkylene group having 1 to 4 carbon atoms, and wherein, in Formula II, R 2 , R 3 , and R 4 are each independently a fluorine atom or a fluorine-substituted alkyl group having 1 to 10 carbon atoms.

The invention claimed is: 
     
       1. A non-aqueous electrolyte, comprising:
 an organic solvent; 
 a lithium salt; and 
 an additive, 
 wherein the additive comprises a compound represented by Formula I and a compound represented by Formula II 
 
       
         
           
           
               
               
           
         
         wherein, in Formula I, R 1  is an alkylene group having 1 to 4 carbon atoms 
       
       
         
           
           
               
               
           
         
         wherein, in Formula II, R 2,  R 3,  and R 4  are each independently a fluorine atom or a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and 
         wherein the additive further comprises a silane-based compound. 
       
     
     
       2. The non-aqueous electrolyte of  claim 1 , wherein the compound represented by Formula I is a compound represented by Formula I-1 
       
         
           
           
               
               
           
         
       
     
     
       3. The non-aqueous electrolyte of  claim 1 , wherein the compound represented by Formula II is a compound represented by Formula II-1 
       
         
           
           
               
               
           
         
       
     
     
       4. The non-aqueous electrolyte of  claim 1 , wherein the compound represented by Formula I is present in an amount of 0.5 wt % to 2 wt % based on a total weight of the non-aqueous electrolyte. 
     
     
       5. The non-aqueous electrolyte of  claim 1 , wherein the compound represented by Formula II is present in an amount of 0.5 wt % to 2 wt % based on a total weight of the non-aqueous electrolyte. 
     
     
       6. A lithium secondary battery, comprising:
 a positive electrode including a positive electrode active material; 
 a negative electrode including a negative electrode active material; 
 a separator disposed between the negative electrode and the positive electrode; and 
 the non-aqueous electrolyte of  claim 1 . 
 
     
     
       7. The lithium secondary battery of  claim 6 , wherein the positive electrode active material is a lithium composite transition metal oxide having an amount of nickel of 50 atm % or more, based on the total amount of transition metals in the lithium composite transition metal oxide. 
     
     
       8. The lithium secondary battery of  claim 6 , wherein the positive electrode active material is a lithium composite transition metal oxide represented by Formula III
   Li x [Ni y Co z Mn w M 1   v ]O 2-p A p   [Formula III]
 
 wherein, in Formula III, 
 M 1  comprises at least one of tungsten (W), copper (Cu), iron (Fe), vanadium (V), chromium (Cr), titanium (Ti), zirconium (Zr), zinc (Zn), aluminum (Al), indium (In), tantalum (Ta), yttrium (Y), lanthanum (La), strontium (Sr), gallium (Ga), scandium (Sc), gadolinium (Gd), samarium (Sm), calcium (Ca), cerium (Ce), niobium (Nb), magnesium (Mg), boron (B), or molybdenum (Mo), 
 A comprises at least one of fluorine (F), chlorine (C1), bromine (Br), iodine (I), astatine (At), or sulfur(S), and 
 0.8≤x≤1.2, 0.5≤y<1, 0<z<0.5, 0<w<0.5, 0≤v≤0.2, and 0≤p≤0.2. 
 
     
     
       9. The lithium secondary battery of  claim 6 , wherein the negative electrode active material comprises a carbon-based negative electrode active material, a silicon-based negative electrode active material, or a mixture thereof. 
     
     
       10. The lithium secondary battery of  claim 6 , wherein the negative electrode active material comprises a silicon-based negative electrode active material.